src: use namespace prefix osmo_* for misc utils

Summary of changes:

s/bcd2char/osmo_bcd2char/g
s/char2bcd/osmo_char2bcd/g
s/hexparse/osmo_hexparse/g
s/hexdump/osmo_hexdump/g
s/hexdump_nospc/osmo_hexdump_nospc/g
s/ubit_dump/osmo_ubit_dump/g
s/static_assert/osmo_static_assert/g
diff --git a/openbsc/src/libtrau/trau_mux.c b/openbsc/src/libtrau/trau_mux.c
index b1fd81d..b8b90bd 100644
--- a/openbsc/src/libtrau/trau_mux.c
+++ b/openbsc/src/libtrau/trau_mux.c
@@ -185,7 +185,7 @@
 			return -EINVAL;
 		if (memcmp(tf.c_bits, c_bits_check, sizeof(c_bits_check)))
 			DEBUGPC(DMUX, "illegal trau (C1-C5) %s\n",
-				hexdump(tf.c_bits, sizeof(c_bits_check)));
+				osmo_hexdump(tf.c_bits, sizeof(c_bits_check)));
 		msg = msgb_alloc(sizeof(struct gsm_data_frame) + 33,
 				 "GSM-DATA");
 		if (!msg)